Restoration treatments enhance early establishment of native forbs in a degraded temperate grassy woodland

Lisa Smallbone, Suzanne Prober, Ian Lunt

Research output: Contribution to journalArticlepeer-review

41 Citations (Scopus)
87 Downloads (Pure)

Abstract

We investigated effects of three understorey restoration treatments – carbon (sugar) addition, spring burning and re-establishment of the perennial native grass Themeda australis (R.Br.) Stapf – on early establishment of eight species of native forbs in a degraded White Box (Eucalyptus albens Benth.) woodland dominated by exotic annuals, in central New South Wales, Australia. Forb seeds and seedlings were introduced to treatments in a randomised, irrigated field trial and monitored for 4–8 months. Treatments significantly altered vegetation structure and composition, resulting in higher native grass and lower exotic grass cover on sugar and burnt plots (especially if seeded with Themeda), a proliferation of broadleaf exotic annuals on burnt plots, and continued high cover of exotic annual grasses and broadleaf annuals on control plots. Forb germination was largely confined to three large-seeded forbs – Bulbine bulbosa (R.Br.) Haw., Dichopogon fimbriatus (R.Br.) J.F.Macbr., and Microseris lanceolata (Walp.) Schultz-Bip., and few germinants of three small-seeded forbs were observed. Overall, germination (% emergence, and seedling numbers after four months) was significantly greater on sugar than burnt and control plots, whilst transplant survival was significantly enhanced by both sugar and burning treatments for up to 8 months after planting. Re-introduced Themeda swards significantly promoted seedling germination and transplant survival in burnt plots. Whilst long-term seedling survival was extremely low due to severe drought, we concluded that: (a) the applied restoration treatments (especially carbon addition) have considerable potential for promoting forb establishment in degraded woodlands; (b) reduced competition with exotic annuals associated with carbon addition outweighed potential disadvantages of reduced nutrient levels; (c) competition with broadleaf annuals and/or exposure to more extreme environments associated with burning may be problematic for forb germination; and (d) Themeda swards may be more conducive to establishment of native forbs than swards of exotic annuals, due to their contrasting growth strategies.
Original languageEnglish
Pages (from-to)818-830
Number of pages13
JournalAustralian Journal of Botany
Volume55
Issue number8
DOIs
Publication statusPublished - 2007

Fingerprint

Dive into the research topics of 'Restoration treatments enhance early establishment of native forbs in a degraded temperate grassy woodland'. Together they form a unique fingerprint.

Cite this